Magnetic separation and discharge of bulk goods



(5. ULLRICH Jan. 26, 1932.

MAGNETIC SEPARATION AND DISCHARGE OF BULK GOODS Filed Dec. 8. 1925Patented Jan. 26, 1932 rares PATENT earl- 6E GrEORGr ULLRICH, 0FMAGDEBURG, GERMANY, ASSIGNOB TO 'ZEBIEDuKRU PP GRUSON- WEB-KAKTIENGESELLSGHAFT,

OF MAGDEBURGQBUGKAU, GERMANY MAGNETIC SEPARATION AND DISCHARGEOFBULILGQODS Application filed December 8; 1925, Serial No. 7434a, and inGermany December 12, 1924.

The present invention relates to means for transporting bull: goods ofthe t 'pe employing conveyor bands which are upported by rollers in sucha manner as to form a trough, so that the bulk goods form deeper layer'11 the centre than at the edges. If during the transport magneticsubstances are to be separated from such goods or material, thedischarge drum is formed into a magnetic separation. drum, and in suchdrums as hitherto constructed the same magnetic power of attraction hasbeen provided throughout the whole width of the conveyor band. It hasbeen necessary, therefore, to use an excitation current sufficientlystrong to ensure that, even in the centre of the band, where thematerial forms the deepest layer, the magnetic substances should beattracted in a reliable manner, whilst tor the thinner layer of materialat the edges of the band, a smaller excitation current would have beensuificient. Such separation drums involve, therefore, higher cost asregards purchase and current than is necessary.

According to the "present invention these drawbacks are avoided byconstructing the separation and discharge drum in such a manner that themagnetic field strength decreases from the centre of the conveyorband-towards its edges. This end may be attained in various ways, forexample, the field gaps of the drum could either be arrangedtransversely of the axis, that is to say extend circumferentially, orthey could be formed into slots extending parallel to the axis; In theformer case the magnetic strength in the circumferential gaps decreasesfrom the centre of the band towards its edges. In the latter casebar-shaped poles are formed in such a manner as to constitute betweenthem field gaps of a width increasing from the centre of the bandtowards its edges.

With the improved construction of drum, a more reliable attraction oithe magnetic substance throughout the whole width of the band can beensured with smaller conductors and current consumption than with drumsas hitherto proposed.

In order that the invention may be clearly Y understood and readilycarried into effect, it

will be described more fully with reterence to the accompanyingdrawings, in which Figures 1 and 2 are longitudinal views, partly insection, of two formsot magnetic separating and discharging drumin whichthe field gaps are circumferential.

In the form of the invention shown in Figure 1 pole discs 1 are mountedon amagnet core 2 and enclose between them excitation coils 3 and 4, thecentralcoil 3 haseither more windings than the lateral coils 4, or it isexcited by a stronger current than the latter, with the result thatthere is a greater'force of attraction over the central field gap thanoverthe lateral fieldgaps. In this case either all pole discs and gapwidths could'be the same or, for the purpose of still further increasingthefield strength of the central field, its pole discs could be madewider than the outer ones, and its gap width could also be made smallerthan that, of the outer fields.

In the example depicted in Figure 2, six pole discs 1 are mounted on themagnet core 2, the two central ones being the widest and the othersnarrower than these. Accordingly a stronger tral pole discs than thatbetween the adjoining discs, and these two fields are stronger than theend fields. The two outer pole discs of each side could be madelongitudinally adjustable on the magnet core by means of the screws 5 orin some other manner, for the purpose of regulating the strength of thefields.

The separation and discharge drum may be suitably enclosed in aprotective casing 10.

What I claim is I 1. A magnetic separator and discharge drum forconveyor bands comprising, a core having a plurality of circular poledisks and an exciting winding, the pole disks nearer the middle of thedrum being wider than those nearer the outside, whereby a magnetic fieldof continuously increasing strength from the outside toward the centerof the drum is produced.

2. In a magnetic separator and discharge drum for conveyor bands, a corehaving pole pieces, defining a plurality of gaps, distributed over theperipheral surface of the drum field exists between the two cen-' nearits edges as well as at the center thereof, and means for creating amagnetic field extending across said gaps, said pole pieces being soarranged as toprovide a continuous increasing field strength from theedges toward the center of the drum.

3. In amagnetic separator and discharge drum for conveyor bands, a core,an exciting winding on said core, a plurality of pole disks distributedalong said core and forming circumferential field gaps, the constructionbeing such that a stronger field is produced between the pole diskslocated near the center of said core than between those located near 5its ends.

l. In a magnetic separator and discharge drum for conveyor hands, acore, a plurality of pole disks on said core forming circumferentialfield gaps, and an exciting winding on said core, the an'inere turns ofsaid exciting winding between the pole disks nearest the middle of saidcore being greater than between the pole disks nearer the ends of aidcore.

5. A magnetic separator and discharge drum for conveyor bandscomprising, a core having a plurality of circular pole disks and anexciting winding, the pole disks near the middle of the drum being widerthan those nearer the outside, said lateral pole disks furthermore beingmounted in an axially adjustable manner.

The foregoing specification signed at Berlin, Germany, this 23rd day ofNovember,

DB. Inc. 11. o. GEORG ULLRICH.

